Category: Transformers

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of_________________?

A. less than 15 A
B. more than 15 A
C. 15 A
D. none of the above

A. Overfluxing protection
B. Buchholz relay
C. Overcurrent protection
D. All of the above

A. short-circuit test
B. back-to-back test
C. open circuit test
D. any of the above

A. provide support to windings
B. reduce hysteresis loss
C. decrease the reluctance of the magnetic path
D. reduce eddy current losses

A. Cellulose
B. Asbestos
C. Mica
D. Glass fibre

A. voltage device
B. current device
C. power device
D. main flux device

A. poor insulation
B. Overload
C. loose connections
D. Core saturation

A. leading power factor
B. lagging power factor
C. unity power factor
D. zero power factor

A. Current
B. Voltage
C. Frequency
D. All of the above

A. Hysteresis losses are reduced
B. Saving in winding material
C. Copper losses are negligible
D. Eddy losses are totally eliminated